U.S. patent application number 14/751467 was filed with the patent office on 2016-01-07 for throttle valve for an internal combustion engine provided with a conditioning circuit.
The applicant listed for this patent is MAGNETI MARELLI S.p.A.. Invention is credited to Marcello Colli, Stefano Musolesi.
Application Number | 20160003167 14/751467 |
Document ID | / |
Family ID | 51589356 |
Filed Date | 2016-01-07 |
United States Patent
Application |
20160003167 |
Kind Code |
A1 |
Musolesi; Stefano ; et
al. |
January 7, 2016 |
THROTTLE VALVE FOR AN INTERNAL COMBUSTION ENGINE PROVIDED WITH A
CONDITIONING CIRCUIT
Abstract
A throttle valve for an internal combustion engine provided with
a valve body, a tubular feeding duct defined in the valve body, a
throttle plate, and an actuating device which controls rotation of
the throttle plate. The actuating device includes an electric motor
and an actuating device conditioning circuit defined in the valve
body. The conditioning circuit includes a tube made of a first
material able to conduct heat, and the valve body is entirely made
of a second metal material and is provided with a seat for housing
the tube, in which is provided a layer of a structural and
heat-conducting resin, interposed between the seat and the
tube.
Inventors: |
Musolesi; Stefano; (Bologna,
IT) ; Colli; Marcello; (Reggio Emilia, IT) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
MAGNETI MARELLI S.p.A. |
Corbetta |
|
IT |
|
|
Family ID: |
51589356 |
Appl. No.: |
14/751467 |
Filed: |
June 26, 2015 |
Current U.S.
Class: |
123/403 ;
29/890.122 |
Current CPC
Class: |
F02D 9/1075 20130101;
F02M 31/102 20130101; F02D 9/1035 20130101; F02D 9/108 20130101;
Y02T 10/126 20130101; F02D 9/1085 20130101; F02D 9/107 20130101;
Y02T 10/12 20130101 |
International
Class: |
F02D 9/10 20060101
F02D009/10 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 26, 2014 |
IT |
BO2014A000349 |
Claims
1. A throttle valve for an internal combustion engine comprising: a
valve body entirely made of a first metallic material; a tubular
feeding duct, defined in the valve body and through which the air
taken in by the internal combustion engine flows; a throttle plate
arranged inside the feeding duct and splined to a shaft mounted in
a rotary manner so as to rotate around a rotation axis between a
maximum opening position and a closing position to open and close
the feeding duct; an actuating device for controlling rotation of
the throttle plate around the rotation axis, the actuating device
including an electric motor and a gear drive for transmitting
motion from the electric motor to the shaft of the throttle plate;
an actuating device conditioning circuit defined in the valve body
including a tube for the passage of conditioning fluid; and wherein
the valve body includes a seat for housing the tube; wherein the
tube is made of a second material able to conduct heat selected
from a group including: steel, aluminum, or copper; and wherein a
substantially uniform layer of a structural and heat-conducting
resin is provided interposed between the seat and the tube and
applied on the entire available surface of the seat so as to allow
fixing of the tube in the seat.
2. The valve as set forth in claim 1, wherein the tube is fixed in
the seat by the layer of structural and heat-conducting resin.
3. The valve as set forth in claim 1, further including a lock for
constraining the tube in the appropriate seat, the lock including a
number of fixing brackets or plates distributed along the entire
length of the tube.
4. The valve as set forth in claim 1, wherein the throttle plate is
made of the same second metal material that makes up the valve
body.
5. The valve as set forth in claim 1, wherein the seat is open on
the upper side and the surface that defines the seat itself has a
shape that is complementary to an outer surface of the tube.
6. The valve as set forth in claim 1, wherein the valve body
includes a tubular housing arranged next to the feeding duct and
housing the electric motor; and wherein the gear drive is arranged
in a chamber of the valve body defined by first and second shells,
the first shell defining a removable lid and the second shell
arranged next to the feeding duct and next to the tubular
housing.
7. The valve as set forth in claim 6, wherein the tube includes a
first branch provided in the upper portion of the second shell
and/or a second branch provided in the upper portion of the tubular
housing.
8. The valve as set forth in claim 7, wherein the tube is
substantially L-shaped.
9. A method to manufacture the throttle valve of claim 1, the
method comprising the steps of: manufacturing the valve body
provided with the seat by causing the second metal material to
undergo a die casting process; applying a trace of the structural
and thermosetting resin on the bottom of the seat; and inserting
the tube into the seat so as to obtain a substantially uniform
layer of the structural and thermosetting resin, which is
interposed between the seat and the tube.
10. The method as set forth in claim 9, wherein the valve body is
subject to a thermal treatment to cause the polymerization of the
structural and thermosetting resin.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] The present application claims priority to and all the
benefits of Italian Patent Application No. BO2014A000349, filed on
Jun. 26, 2014, which is hereby expressly incorporated herein by
reference in its entirety.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention elates to a throttle valve for an
internal combustion engine provided with a conditioning
circuit.
[0004] 2. Description of the Related Art
[0005] A throttle valve, which is arranged upstream of an intake
manifold and adjusts the flow rate of the air which is fed to the
cylinders, is normally provided in internal combustion engines.
Conventional throttle valves typically have a valve body provided
with a tubular feeding duct through which the intake or compressed
air for the internal combustion engine flows. A throttle plate is
housed in the feeding duct and is splined to a rotating shaft to
rotate between an opening position and a closing position of the
feeding duct. The rotation of the throttle valve plate is
controlled by an actuator device which typically includes an
electric motor coupled to the throttle valve plate shaft via a gear
drive and at least one spring which pushes the throttle valve plate
shaft towards the closing position (or rather towards a limp-home
position close to the closing position).
[0006] The electric motor has a cylindrical body which is arranged
in a tubular housing of the valve body arranged by the side of the
feeding duct. The gear drive is arranged in a chamber of the valve
body, which is defined by two shells: a first shell defining a
removable lid and a second shell arranged next to the feeding duct
and next to the tubular housing.
[0007] The valve body further includes a conditioning circuit which
is defined by a channel, which may assume various conformations and
routes. Where the channel is substantially L-shaped, it has a major
branch provided in the upper portion of the second shell and a
minor branch provided in the upper portion of the tubular housing.
The channel is in hydraulic communication with a pump, which
circulates conditioning fluid and feeds the channel itself for
conditioning the various parts of the throttle valve.
[0008] Published European Patent No. EP1348850 describes, for
example, a throttle valve provided with a heating circuit adapted
to prevent the freezing of the valve itself provided with an
elastically deformable tube made of a fuel and oil resistant
rubberized fabric arranged in a variable section channel of an
appendix of the valve body having a smaller diameter than the
diameter of the elastically deformable tube which is arranged
inside it. Published German Patent No. DE19625154 instead describes
a device for heating a throttle valve made with an appropriately
shaped tube which is connected to the valve body via mechanical
fixing, such as a pair of brackets for example. Further, a layer of
heat-conducting paste is interposed between the tube of the heating
device and the valve body. The heat-conducting paste does not have
a structural function and therefore mechanical fixing is are needed
to connect the tube to the valve body.
[0009] The entire valve body of most conventional throttle valves
is made of metallic material, such as aluminum, and is monolithic
(i.e. is formed seamlessly in one piece).
[0010] The valve body (i.e. the second shell, the feeding duct, and
the tube housing) is made by casting (normally die-casting) and, if
needed, is then mechanically machined. Pinholes and/or micro air
bubbles may form in the valve body because the material is injected
at relatively high temperatures (in the order of 700.degree. C.),
at equally high pressures (in the order of 1000 bar), and very
rapidly for manufacturing the valve body by casting (normally
die-casting). The pinholes and/or micro bubbles are difficult to
see with unaided eye (but are visible only under X rays) and are
difficult to identify during the step of setting and tuning the
throttle valve.
[0011] Such pinholes and/or micro bubbles are particularly
dangerous because with the aging of the valve body and, in the case
of relatively high pressures involved, the passage of conditioning
fluid in the conditioning circuit channel may put different micro
bubbles into mutual communication and thereby cause the formation
of channels for the passage of conditioning fluid towards the other
components, in particular towards the electric motor, towards the
feeding duct, or towards the outside environment.
SUMMARY OF THE INVENTION
[0012] It is the object of the present invention to provide a
throttle valve for an internal combustion engine provided with a
conditioning circuit, where the throttle valve is free from the
drawbacks of the prior art and is easy and cost-effective to make
at the same time.
[0013] It is a further object of the present invention to provide a
method for making a throttle valve for an internal combustion
engine which is free from the drawbacks of the prior art and which
is easy and cost-effective to implement at the same time.
[0014] The present invention overcomes the disadvantages in the
related art in a throttle valve for an internal combustion engine.
The throttle valve includes a valve body entirely made of a first
metallic material. A tubular feeding duct is defined in the valve
body, and air taken in by the internal combustion engine flows
through the tubular feeding duct. A throttle plate arranged inside
the feeding duct is splined to a shaft mounted in a rotary manner
so as to rotate around a rotation axis between a maximum opening
position and a closing position to open and close the feeding duct.
An actuating device controls the rotation of the throttle plate
around the rotation axis and includes an electric motor and a gear
drive transmits motion from the electric motor to the shaft of the
throttle plate. An actuating device conditioning circuit is defined
in the valve body and includes a tube for the passage of a
conditioning fluid. The valve body includes a seat for housing the
tube. The tube is made of a second material able to conduct heat
and may be selected from a group including steel, aluminum, or
copper. A substantially uniform layer of a structural and
heat-conducting resin is provided interposed between the seat and
the tube and applied on the entire available surface of the seat so
as to allow fixing of the tube in the seat.
[0015] The present invention is also directed toward a method of
manufacturing the throttle plate. The method includes the steps of:
manufacturing the valve body provided with the seat by causing the
second metal material to undergo a die casting process; applying a
trace of the structural and thermosetting resin on the bottom of
the seat; and inserting the tube into the seat so as to obtain a
substantially uniform layer of the structural and thermosetting
resin, which is interposed between the seat and the tube.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] Other objects, features, and advantages of the present
invention will be readily appreciated as the same becomes better
understood after reading the subsequent description taken in
connection with the accompanying drawing wherein:
[0017] FIG. 1 is a perspective, partially exploded view with parts
removed for clarity of a throttle valve made according to the
present invention.
[0018] FIG. 2 is a front view with parts removed for clarity of the
throttle valve in FIG. 1.
[0019] FIG. 3 is a plan view with parts removed for clarity of the
throttle valve in FIG. 1.
[0020] FIG. 4 is a perspective view of a conditioning circuit of
the throttle valve in FIG. 1.
[0021] FIGS. 5 and 6 illustrate the detail of the conditioning
circuit in FIG. 4 in various different, subsequent steps of the
manufacturing method of the throttle valve in FIG. 1 from the
front.
DETAILED DESCRIPTION OF THE INVENTION
[0022] With reference now to the drawing(s), in FIGS. 1 and 2,
numeral 1 indicates as a whole an electronically controlled
throttle valve for an internal combustion engine (not shown, but
generally known in the art). The throttle valve 1 includes a valve
body 2 housing an electric motor 3 (see FIG. 2), a tubular circular
section feeding duct 4 through which the air aspirated by the
internal combustion engine flows, and a throttle valve plate 5
(diagrammatically shown with a dashed line), which is circular,
engages the feeding duct 4, and rotates between an opening position
and a closing position of the feeding duct 4 under the bias of the
actuator device. The throttle valve plate 5 is splined onto a shaft
6 having a longitudinal rotation axis 7 to rotate between the
opening position and the closing position under the bias of the
actuator device.
[0023] As shown in FIG. 2, the actuator device includes the
electric motor 3 which is coupled to the shaft 6 itself via a gear
drive 8, a return spring coupled to the shaft 6 (not shown) and
adapted to rotate the throttle valve 5 towards the closing
position, and a contrast spring coupled to the shaft 6 (not shown)
and adapted to rotate the throttle valve plate 5 towards a partial
opening position or limp-home position defined by a stopper body
(not shown) against the bias of the return spring.
[0024] The electric motor 3 has a cylindrical body, which is
arranged in a tubular housing 9 (shown in FIG. 1) of the valve body
2 arranged by the side of the feeding duct 4 and is maintained in a
determined position in the tubular housing 9 by a metallic plate
provided with a pair of female electric connectors 10 (see FIG. 2),
which are electrically connected to the electric motor 3 and are
adapted to be engaged with a pair of respective male electric
connectors 11 (see FIG. 1).
[0025] The gear drive 8 is arranged in a chamber 12 (see FIG. 2) of
the valve body 2, which is defined by a first shell 13* and a
second shell 13**. The first shell 13* defines a removable lid 13*
(see FIG. 1) and a second shell 13** is arranged by the side of the
feeding duct 4 and next to the tubular housing 9.
[0026] As shown in FIGS. 1 and 2, the throttle valve 1 includes an
inductive contactless type position sensor, which is coupled to the
shaft 6 and is adapted to detect the angular position of the shaft
6 (and, thus, of the throttle valve plate 5) to allow a feedback
control of the position of the throttle valve plate 5 itself. The
position sensor includes a rotor 14 (see in FIG. 2) integral with
the shaft 6, and a stator 15 (see FIG. 1) supported by the
removable lid 13* and arranged facing the rotor 14 in use.
[0027] As shown in FIG. 1, the removable lid 13* is provided with a
female electric connector 16, which includes a series of electric
contacts (not shown in detail): two electric contacts are connected
to the male electric connectors 11 adapted to supply the electric
motor 3, while other electric contacts are connected to the stator
15 of the position sensor.
[0028] The valve body 2 is entirely made of a first material,
internally defines the feeding duct 4, and includes the tubular
housing 9, which is arranged by the side of the feeding duct 4 and
houses the electric motor 3 and the chamber 12, which houses the
gear transmission 8 and is closed by the removable lid 13*. In
other words, the shell 13**, the feeding duct 4, and the tubular
housing 9 are made of the first material
[0029] In one embodiment, the valve body 2 (i.e. the shell 13**,
the feeding duct 4, and the tubular housing 9) is made of a
metallic material, such as aluminum. Advantageously, the throttle
valve 5 is made of the first metallic material of which the valve
body 2 is made. Alternatively, the throttle valve plate 5 is made
of a metallic material which is different from the metallic
material of which the valve body 2 is made, but which behaves
similarly to the first metallic material of which the valve body 2
is made. In this manner, the two parts which cooperate to define
the closing of the feeding duct 4 are made of the same material (or
in cases of mutually similar metallic materials) and thus have
substantially the same type of behavior to heat variations and to
aging.
[0030] As shown in FIG. 3, the valve body 2 includes a conditioning
circuit 17 which, in turn, includes a seat 18 and a tube 19. In
plan view, the seat 18 is substantially L-shaped and has a major
branch 18* provided in the upper portion of the shell 13**, a minor
branch 18** provided in the upper portion of the tubular housing 9,
and a curved connecting stretch 18*** between the major branch 18*
and the minor branch 18**. The seat 18 accommodates the tube 19
inside, which is made of a second material and is also
substantially L-shaped having a major branch 19*, a minor branch
19**, and a curve connecting stretch 19*** between the major branch
and the minor branch. In one embodiment, the second material of
which the tube 19 is made is chosen from a group including: steel
(advantageously, stainless steel), copper, aluminum, or any other
material with good heat exchange capacity. As shown in detail in
FIGS. 5 and 6, in section, the seat 18 is circular segment shaped,
is open on the top, and the shape of the inner surface 20 which
defines the seat 18 itself is substantially complementary to the
outer surface 21 of the tube 19. The tube 19 is in hydraulic
communication with a pump (not shown) which circulates conditioning
fluid and feeds fluid to the tube 19 to condition the various parts
of the throttle valve 1.
[0031] The valve body 2 (i.e. the shell 13**, the feeding duct 4,
and the tube housing 9) is made by casting (normally die-casting)
and, if needed, is then mechanically machined. In other words, the
first material of which the valve body 2 (i.e. the shell 13**, the
feeding duct 4, and the tubular housing 9) is made by injection
co-molding so as to define the seat 18 provided for housing the
tube 19.
[0032] As shown in detail in FIGS. 3-6, the tube 19 is inserted in
the seat 18 provided in the valve body 2 once the casting process
of the valve body 2 itself is completed.
[0033] A trace T of structural and heat-conducting resin is applied
once the casting process of the valve body 2 is completed. The
trace T of the structural and heat-conducting resin is deposited
with a specific application tool, advantageously on the bottom of
the seat 18 itself (as shown in FIGS. 4 and 5). In one embodiment,
a structural and heat-conducting resin is used, the basic fluidity
of which is variable from liquid to semi-solid. In one embodiment,
a structural heat-conducting and thermosetting resin is used. In
other alternative embodiments, the structural heat-conducting resin
is epoxy, or polyurethane or acrylic based.
[0034] It will be appreciated that the resin used for the trace T
has structural value to allow the anchoring of the tube 19 in the
seat 18 and, at the same time, allows the transmission of heat
between the conditioning fluid which circulates the tube 19 and the
various parts of the throttle valve 1.
[0035] After having deposited the trace T of the structural and
heat-conducting resin, the tube 19 is inserted in the seat 18. The
resin present on the bottom of the seat 18 moves upwards so as to
completely skim the inner surface 20 of the seat 18 and partially
the outer surface 21 of the tube 19 so as not to protrude from the
seat 18 towards an upper surface 22 of the valve body 2. A
substantially uniform layer S of structural and heat-conducting
resin is thus formed between the seat 18 and the tube 19 (see FIG.
6).
[0036] In one embodiment, the valve body 2 is substantially
subjected to a thermal treatment (e.g. via infrared, induction, or
via passage in polymerization ovens) to allow to complete the
polymerization of the structural and heat-conducting resin.
Alternatively, the structural and heat-conducting resin may be of
the thermosetting type. A monocomponent structural and
heat-conducting resin or a bicomponent structural and
heat-conducting resin may be advantageously applied; the
polymerization temperature of the structural and heat-conducting
resin is variable as a function of the components of the structural
and heat-conducting resin itself.
[0037] Once polymerized, the resin can constrain the tube 19 to the
seat 18 and further allows the heat exchange between the
conditioning fluid and the air aspirated by the internal combustion
engine which flows through the tubular feeding duct 4 defined in
the valve body 2. Furthermore, the structural and heat-conducting
resin has a high resistance to thermal shocks and relatively high
working temperatures (in the order of 380.degree. C.) equal to
double the temperatures which can be found in the valve body 2.
[0038] In one embodiment, the seat 18 is open on the top and the
tube 19 is rigidly constrained to the seat 18 exclusively via the
structural and heat-conductive resin. In other words, there are no
mechanical locks constraining the tube 19 in the specific seat
18.
[0039] In one variant, a mechanical lock (not shown) of the tube 19
in the specific seat 18 are provided, as for example a number of
fixing brackets or plates distributed along the entire length of
the tube 19.
[0040] It will be appreciated that the conditioning circuit 17 may
have alternatively different conformations from the substantially
L-shape conformation described above. In particular, according to
alternative variants, the conditioning circuit 17 (i.e. the seat 18
and tube 19) has a rectilinear shape and is provided in the upper
portion of the shell 13** or in the upper portion of the tubular
housing 9.
[0041] The throttle valve 1 described above has many advantages. In
particular, the valve body 2 of the throttle valve 1 described
above is simple and cost-effective to make because it can be easily
made by injection molding the valve body 2 (i.e. the shell 13**,
the feeding duct 4, and the tubular housing 9) and subsequently
applying the resin for locking the tube 19 in the seat 18.
Furthermore, the valve body 2 of the throttle valve 1 described
above has extremely low weight and manufacturing costs. Moreover,
the throttle valve 1 allows to prevent the passage of conditioning
fluid used in the conditioning circuit and contained in the tube 19
towards, for example, the electric motor 3, the feeding duct 4, or
towards the outside environment during use, independently from
aging in use.
[0042] The invention has been described in an illustrative manner.
It is to be understood that the terminology which has been used is
intended to be in the nature of words of description rather than of
limitation. Many modifications and variations of the invention are
possible in light of the above teachings. Therefore, within the
scope of the appended claims, the invention may be practiced other
than as specifically described.
* * * * *